Extension method to remove not primitive property of an object-CodePudding

I'd like an extension method to create an object based on another but keep only the primitive properties. This object will be dumped into a log file in JSON format for logging.

Based on the classes shown below, in this sample, the created object should keep only these properties :

public string  FirstName { get; set; }
public string LastName { get; set; }
public int Age { get; set; }

I am using .NET Framework 4.7

How can I do this?

// To use like this
var order = new Order();
var forLog = order.RemovePrimitives();

// Sample of classes
public class Order
{
    public string  FirstName { get; set; }
    public string LastName { get; set; }
    public int Age { get; set; }
    public List<Item> Items { get; set; }
    public Address Address { get; set; }
}

public class Item{}

public class Address{}

public static class Extensions
{
    public static string RemovePrimitives(this object obj)
    {
        // I need to create an anonymous, named 'TheNewObjectHere' object but only with primitives
        // I will dump the object to push to a log file. I need only primitives
        return JsonConvert.SerializeObject(TheNewObjectHere, Formatting.Indented);
    }
}

Thanks

CodePudding user response：

try this

public static class Extensions
{
    public static string RemovePrimitives(this object obj)
    {
        var jsonObj = JObject.FromObject(obj);

        var propToRemove = jsonObj.Properties().Where(i => !i.Value.GetType().ToString()
                                                            .Contains("JValue")).ToList();

        foreach (var prop in propToRemove) prop.Remove();

        return jsonObj.ToString();
    }
}

CodePudding user response：

You can use reflection to get primitive properties and then use JObject to build a JSON object dynamically.

public static readonly Type[] AdditionalPrimities = new[] { typeof(decimal), typeof(string) };

    public static string RemovePrimitives<T>(this T obj)
    {
        var jObj = new JObject();
        var props = GetPrimitiveProperties(obj);

        foreach (var item in props)
        {
            var value = item.GetValue(obj);
            if (value != null)
            {
                jObj.Add(item.Name, new JValue(value));
            }
        }

        return jObj.ToString(Newtonsoft.Json.Formatting.Indented);
    }

    public static PropertyInfo[] GetPrimitiveProperties<T>()
    {
        var properties = typeof(T)
            .GetProperties(BindingFlags.Instance | BindingFlags.Public)
           .Where(r => r.PropertyType.IsPrimitive || (r.PropertyType.IsGenericType && Nullable.GetUnderlyingType(r.PropertyType) != null) || AdditionalPrimities.Contains(r.PropertyType))
            .Select(r => r)
            .ToArray();


        return properties;
    }

    public static void Main()
    {
        var order = new Order { FirstName = "abc", LastName = "cde", Address = new Address(), Age2 = 3, Age = 1 };
        var final = order.RemovePrimitives();

        Console.WriteLine(final);
    }

Fiddle